The control of fine particles by filtration alone depends on capturing the particles using three possible mechanisms: impaction, interception, or diffusion, with the dominant collection mechanisms for submicron-sized particles known to be interception and diffusion. Filters can be designed and manufactured with small pore sizes such that submicron particles are collected with high efficiency. However, such filters exhibit a substantial pressure drop for gas flowing therethrough with an associated rapid increase in back pressure as the particles collect on the filter surface.
Alternatively, a decrease in pressure drop across the filter can be obtained by employing increased pore sizes, however the collection efficiency of such larger pore size filters is not acceptable. As such, a balance between pore size, need for low pressure drop and collection efficiency is a theoretical limitation for all filters that rely on primary filtration collection mechanisms.
In an effort to overcome the above-stated limitation, electrostatic mechanisms have been developed to drive particles to a collection surface without plugging filter pore openings. However, conventional electrostatic collectors have been limited by long distances that particles must travel in order to reach a grounded surface. Accordingly, a particulate collection apparatus and process for combining high particle collection efficiency, low filter pressure drop and regeneration potential that is applicable for high temperature processes would be desirable.